9 Photos - Jun 1, 2014
Photo: Flexible VHF/UHF Antennas for comparison (top to bottom):
1. TYT TH-UVF9 stock antenna
2. Yaesu FT-60R stock antenna
3. 1990 vintage Larsen KūlDuckie KD4-270 antenna
4. Diamond RH771 144/430 MHz antennaPhoto: This label on the TYT TH-UVF9 antenna claims 136-174 MHz and 400-480 MHz coverage.
This is an ambitious claim for a shortened flexible antenna.
The VNA measurement shows a significant impedance mismatch over the 136-174 MHz range.Photo: Handheld antenna characteristics vary significantly depending on counterpoise coupling and interaction with objects in the near field.
This test jig of a lumber tie plate on a camera tripod was made to provide a common fixed counterpoise for these measurements.Photo: Here is the MiniVNA Pro secured to the antenna test jig with a Velcro strap. The computer running vna-J software was connected via Bluetooth.Photo: The antenna testing was conducted outdoors to reduce the effects of objects in the near field upon measurements.Photo: TYT TH-UVF9 Antenna SWR & RL vs Frequency.  Note that the SWR is over 3:1 from 144-148 MHz.  
At 145 MHz the return loss -5.462 dB yields 28% reflected power.Photo: Yaesu FT-60R Antenna SWR & RL vs FrequencyPhoto: Larsen KD4-270 KūlDuckie Antenna SWR & RL vs FrequencyPhoto: "Diamond RH771" Antenna SWR & RL vs Frequency
(This antenna is a Chinese counterfeit)
Compare with http://waynemerry.wordpress.com/tag/diamond-rh771-dual-band-antenna/